Proposed is an investigation of methodological issues in the long--term recall of physical activity (both occupational and leisure time). The study will be conducted in a sample of 300 white men and women and 50 blacks age 45-69 yrs., participants in the Buffalo Blood Pressure Study. The Buffalo Blood Pressure Study was an epidemiological investigation conducted in a random sample of residents of the City of Buffalo in 1961, 15 yrs of age and older. Detailed information was gathered on a number of lifestyle habits, sociodemographic and psychological characteristics including detailed data regarding occupational and leisure time physical activity. Proposed here is reinterview of 350 participants who are alive, residents of Western New York and with age less than 70 yrs. regarding their physical activity 30 years ago and currently. Two technique will be used in the reinterview: (1) standard interview techniques (n=200) and (2) cognitive interview techniques (n=100). Data on physical activity gathered in 1961 will be compared with recalled data in order to determine the validity of long-term recall. In addition original and current physical activity, as well as other sociodemographic characteristics will be analyzed to determine their role in distinguishing participants with "good recall" from those with "poor recall". Finally, the standard and the cognitive interview techniques will be compared to test whether or not it is possible to increase accuracy of long-term recall of physical activity with the use of cognitive techniques. The proposed study will address important methodological issues with regard to the validity and means to improve the quality of long-term recall of lifestyle habits in general and physical activity in particular. At this time, limited information is available on the application of cognitive techniques to epidemiologic research. The information produced by the proposed investigation will help improve the efficiency of interview techniques and quality of data in epidemiological studies and health surveys.